The present invention relates to texturizing outer surfaces of workpieces in general, and more particularly to a method of and an apparatus for embossing such outer surfaces with embossing patterns.
There are already known various arrangements for providing pressed, glossy or embossed texture on pressed metal sheets, punches, rollers, belts, foils or the like. So, for instance, there are already known double band presses which apply surface impressions to advancing plate-shaped workpieces by means of endless pressing belts.
By using such a double belt press, it is, for instance, possible to coat a workpiece with a foil. In this case, the pressing belts, which are constructed as steel belts, have a correspondingly prepared surface which either is provided with texturizing portions or is smooth, depending on whether the outer surface of the workpiece is to be texturized or smooth.
Consequently, depending on the respective application or needs, there are to be used correspondingly constructed and configured belts, inasmuch as there are presently available only pressing belts which are provided either with an embossed surface or with a smooth surface. Naturally, a belt exchange is relatively time-consuming and thus rather expensive so that, in the final analysis, it makes sense from the economical point of view to utilize this approach only when substantial lot sizes are to be produced with one pressing band type. Therefore, desires and requirements of consumers with respect to the configuration and texture of the surfaces of the workpieces can be taken into consideration only to an insufficient extent.
A further important disadvantage of the above approach is the currently existing need for the expensive and costly keeping of a stock of pressing belts, inasmuch as separate belts have to be available for each different texturization of the workpiece surfaces. Especially in view of the fact that the textures or reliefs of the workpiece surfaces are to a certain extent subject to fashion demands, the life span of the corresponding pressing belts cannot be fully utilized in many instances. This also contributes to relatively low efficiency and economy of the heretofore known texturizing processes.
As a sum total of the aforementioned disadvantages, there is obtained the result that the desirable design freedom with respect to the configurations of the pressing belts is not possible in an economically supportable framework.
The same is obviously also true when, instead of the pressing belts which then act as embossing belts, pressing metal sheets, pressing punches, pressing rollers or pressing foils are being employed for the texturizing of workpiece surfaces. In this connection, the above-discussed problems also exist during the fabrication of an embossed, a pressed or a glossy texture.